WERTHEIMER: When it comes to diet advice, there are a lot of conflicting ideas out there. And a recent study published in the medical journal The Lancet, which has gotten a ton of attention, adds to that debate. The findings challenge some of the traditional thinking about what defines a healthy diet. We'll take your questions and talk about this study with NPR food and health correspondent Allison Aubrey. Allison, this is yet another study that looks at the role of fat and carbs and how our diet choices can influence our health. Tell us about the study.

ALLISON AUBREY, BYLINE: Well, researchers looked at the dietary habits of tens of thousands of people in 18 countries, including many lower-income countries - so places like Bangladesh and India - and some middle-income countries, too - Turkey and Poland. What they found is that people who get most of their calories from carbohydrates had about a 25 percent higher risk of premature death compared to people who ate fewer calories.

Now, this is kind of confusing because there are lots of things that are carbohydrate-rich, right? I mean, a Jelly Belly has a lot of carbohydrates. Candy has a lot of carbohydrates, but so do fruits and whole grains. So here's the part of the study that helps give insight about the impact of diet on our health.

The next part of the study researchers looked at people who consumed a lot of vegetables, a lot of beans, a lot of fruits - so these are the good carbohydrates you can think of. They had a lower risk of death. Now, when you put these two things together, I think the strong suggestion here is that it's these refined carbohydrates and sugars - all the packaged crackers and chips - these seem to be driving the risk, at least that's the conclusion of some of the scientists who looked at this.

WERTHEIMER: And what was the reaction?

AUBREY: Well, you know, I think some nutrition experts look at this. And they say, hey, look, this is more evidence that the war on fat that we had - these messages to eat less fat - really shifted dietary habits so that people started consuming more carbs. People didn't really get the message to eat, you know, whole grains and fruits and vegetables. What they seemed to get the message on was to eat more refined carbohydrates. And this, certainly, didn't do any favors for our waistlines or for our health.

WERTHEIMER: Well, let's find out what listeners want to know. Here's a comment from a health teacher.

UNIDENTIFIED WOMAN #4: (Unintelligible). And I pretty much tell my kids moderation. I know the Framingham studies show that it was cholesterol and saturated fat, but now they're questioning that. So I tell them moderation. So you don't want too much fat. You don't want too much sugar and eat lots of fruits and vegetables for the vitamins and minerals.

AUBREY: I love that. I love banging the moderation drum. I think it's excellent advice. I mean, one thing I would point out - she mentioned the Framingham Study. That's one of these big studies where they follow tens of thousands of people for decades. And then they see how their diets influence the risk of disease. And what studies like this show us is really important.

So for instance, you'll hear a study that found, oh, people who consume a lot of red meat - they have a higher risk of colorectal cancer. Now, when you look at these studies, almost without fail, what you see is it's the dose - it's the amount that can increase the risk of disease. So if you look at somebody eating a little bit of red meat, you don't see much of an increased risk of the colorectal cancer, if any.

So I think the bottom line is that a little bit of something - a little bit of red meat, a little bit of sugar - that's not going to increase your risk of heart disease or cancer. It's when your pattern of eating includes a lot of these things, that's where you see the increased risk.

WERTHEIMER: All right. Let's hear from another listener.

KATE BERMAN: Hi. My name is Kate Berman (ph). I'm 75. And for the past year and a half, I've been on a plant-based diet - off meat, dairy, processed food and on to a delicious real whole food diet. I've been diagnosed with atherosclerosis heart disease. I brought my cholesterol down to 154. My low cholesterol is 77. And they had called me a pre-diabetic, but my blood sugars are now at normal levels. Oh, and I lost 40 pounds and an inch off my waist. And I eat as much as I want. And I love the food I'm eating. Thanks for asking.

AUBREY: You know, when I listen to this, the thing that jumps out at me - well, there's a lot there. But one of the things she mentioned is that she had been considered to be pre-diabetic. That means her blood sugar levels were elevated. And she's certainly not alone. There are 80 million Americans who have elevated blood sugar levels. This is a huge problem because everybody knows that when you go on to develop diabetes, your risks of everything go up.

So I think the point here is that we tend to get lost in the weeds of - oh, is it carbs or is it fat? You know, we have this obsession with this sort of carb-fat fight. And I think in some ways, it's just asking the wrong question because we should kind of focus on what we do know. What she pointed out - she said she lost, I think, 14 pounds. There was this very, very important study done about 10 years ago called the Diabetes Prevention Program study.

And it found that when people change their diets in really moderate ways - they eliminate sugary drinks, sugary cereals, cut the refined carbs, started exercising just a little. If they made enough of a move to cut their body weight by 5 percent, then their risk of developing diabetes was cut 60 percent. The point here is that you can use dietary change to reverse these high blood sugar levels. And the story we just heard from Kate, I think, you know, just shows the strength of this.

WERTHEIMER: And next week on the Call-In, with wildfires raging in the western U.S., we want to hear about your experiences with wildfire. Have you been through one? How did your community cope? What has it done since to minimize the impact of fires in the future? Please call in at 202-216-9217. Be sure to include your full name, contact info and where you're from. That number again is 202-216-9217. And we may use your question on the air.